Typically, as a method for preserving a biological component (for example, animal cells), there is a method which involves dispersing cells in a freeze preservative liquid, placing the resulting liquid in a tube for freeze preservation, and freeze-preserving the liquid in the tube (for example, Non Patent Literature 1). The major freeze preservative liquids to be used include a liquid obtained by adding 10% dimethyl sulfoxide into a culture medium or serum, and commercially available ones. A techniques have been also studied for holding and preserving frozen cultured cells in a culture vessel (Patent Literature 1).
Techniques for chilled preservation have been also studied. For example, Euro-Collins liquid (Non-Patent Literature 2), UW liquid (University of Wisconsin liquid) (Non Patent Literature 3), ET-kyoto liquid (Patent Literature 2), and the like have been known as a cell/tissue-preservation liquid for chilled preservation, which have been conventionally used. Patent Literature 3 describes a preservation solution for eyeball to be used for corneal transplantation that contains hyaluronic acid or its salt.
ThelioKeep, CPS-1, and the like are marketed as a commercial chilled preservation liquid. ThelioKeep contains catechin as an active ingredient and is applied to the preservation of tissues, particularly epithelial and endothelial skins and nerve tissues (Non Patent Literature 4 and Patent Literature 4). CPS-1, in which the composition of salts is optimized, is a reagent tailored for floating cells (Patent Literature 5).
A method for preserving cells, focusing attention on phosphorylcholine as a phospholipid constituting the cell membrane has been also reported (Non Patent Literature 5).
In addition, HyStem (trademark) has recently been commercially available, which is a modified hyaluronic acid for subjecting cells to 3-dimensional embedding culture (Non Patent Literatures 6, 7, and 8).
Meanwhile, Non Patent Literature 9 discloses the use of a hydrogel using phenylboronic acid-modified chitosan in the field related to diabetes treatment. Patent Literature 6 discloses a technique for using a hydrogel using phenylboronic acid-modified hyaluronic acid together with a therapeutic agent for diabetes in the field of the drug delivery system.